Effect of pneumatic tube delivery system rate and distance on hemolysis of blood specimens

Comparison of the speed and quality of innovative and traditional pneumatic tube system transport outside of an emergency laboratory

Background

Ensuring the rapidity and accuracy of emergency laboratory test results is especially important to save the lives of patients with acute and critical conditions. To better meet the needs of clinicians and patients, detection efficiency can be improved by reducing extra-laboratory sample turnaround times (TATs) through the use of innovative pneumatic tube system (PTS) transport for sample transport. However, concerns remain regarding the potential compromise of sample quality during PTS transit relative to that occurring with manual transportation. This study was performed to evaluate the efficacy of an innovative PTS (Tempus600 PTS) relative to a traditional PTS in terms of sample transit time, sample quality, and the concordance of analytical results with those obtained from manually transported samples.

Methods

In total, 30 healthy volunteers aged >18 years were recruited for this study, conducted for five consecutive days. Venous blood samples were collected from six volunteers per day at fixed timepoints. From each volunteer, nine blood samples were collected into tubes with tripotassium ethylene diamine tetraacetic acid anticoagulant, tubes with 3.2 % sodium citrate, and serum tubes with separation gel (n = 3 each) and subjected to all tests conducted in the emergency laboratory in our hospital. 270 blood samples from 30 healthy volunteers were transported and analyzed, yielding 6300 test results. The blood samples were divided randomly into three groups (each containing one tube of each type) and transported to the emergency laboratory manually and with Tempus600 PTS and conventional Swisslog PTS, respectively. The extra-laboratory TATs, sample quality, and test results of the transported blood samples were compared.

Results

The sample quality and test results did not differ according to the delivery method. The TAT was much shorter with the Tempus600 than with the other two transport modes (58.40 ± 1.52 s vs. 1711.20 ± 77.56 s for manual delivery and 146.60 ± 1.82 s for the Swisslog PTS; P = 0.002).

Conclusion

Blood sample transport with the Tempus600 PTS significantly reduced the extra-laboratory TAT without compromising sample quality or test result accuracy, thereby improving the efficiency of sample analysis and the services provided to clinicians and patients.

Comparison of a two-step Tempus600 hub solution single-tube vs. container-based, one-step pneumatic transport system

OBJECTIVES

Efficient and timely transportation of clinical samples is pivotal to ensure accurate diagnoses and effective patient care. During the transportation process, preservation of sample integrity is crucial to avoid pre-analytical aberrations on laboratory results. Here, we present a comparative analysis between a two-step Tempus600 hub solution single-tube and a one-step, container-based pneumatic transport system (PTS) from Airco, for the in-house transportation of blood samples.

METHODS

Ten blood samples from healthy volunteers were split in 10 mL collection tubes filled at full or half capacity for transportation with the two PTS (about 250 m). To compare the impact of transportation, markers of hemolysis such as lactate dehydrogenase (LDH), potassium (K+), and the hemolysis index (HI), were determined. Additionally, differences in HI in routine samples and repeated transportation was investigated. To assess and compare the mechanistic impact profiles, we recorded the acceleration profiles of the two PTS using a shock data logger.

RESULTS

Transportation using the Tempus600 hub solution resulted in 49 and 46 % higher HI with samples filled to total or half capacity, respectively. Routine samples transported with the Tempus600 hub solution showed a higher median HI by 23 and 33 %. Additionally, shock logger analysis showed an elevated amount of shocks (6.5 fold) and shock intensities (1.8 fold).

CONCLUSIONS

The Tempus600 hub solution caused an increased number of unreportable LDH or K+ results based on the hemolysis index. However, it was only statistically significant for LDH (p<0.01 and p<0.08) - while the comparisons for K+ were not statistically significant (p<0.28 and p<0.56).

Diagnostic sample transport via pneumatic tube systems: data logger and their algorithms are sensitive to transport effects

OBJECTIVES

Many hospitals use pneumatic tube systems (PTS) for transport of diagnostic samples. Continuous monitoring of PTS and evaluation prior to clinical use is recommended. Data loggers with specifically developed algorithms have been suggested as an additional tool in PTS evaluation. We compared two different data loggers.

METHODS

Transport types - courier, conventional (cPTS) and innovative PTS (iPTS) - were monitored using two data loggers (MSR145® logger, CiK Solutions GmbH, Karlsruhe, Germany, and a prototype developed at the University Medicine Greifswald). Data loggers differ in algorithm, recording frequencies and limit of acceleration detection. Samples from apparently healthy volunteers were split among the transport types and results for 37 laboratory measurands were compared.

RESULTS

For each logger specific arbitrary units were calculated. Area-under-the-curve (AUC)-values (MSR145®) were lowest for courier and highest for iPTS and increased with increasing recording frequencies. Stress (St)-values (prototype logger) were obtained in kmsu (1,000*mechanical stress unit) and were highest for iPTS as well. Statistical differences between laboratory measurement results of transport types were observed for three measurands sensitive for hemolysis.

CONCLUSIONS

The statistical, but not clinical, differences in the results for hemolysis sensitive measurands may be regarded as an early sign of preanalytical impairment. Both data loggers record this important interval of beginning mechanical stress with a high resolution indicating their potential to facilitate early detection of preanalytical impairment. Further studies should identify suitable recording frequencies. Currently, evaluation and monitoring of diagnostic sample transport should not only rely on data loggers but also include diagnostic samples.

Influence of pneumatic tube delivery system on laboratory results

INTRODUCTION

The pneumatic tube system (PTS) is an automated and fast modality of transportation of biological samples, but it has been reported to induce preanalytical errors.

AIM

To study the influence of transportation by PTS on biochemistry tests which are particularly sensitive to haemolysis and atmospheric pressure variation.

MATERIALS AND METHODS

We compared laboratory results of arterial blood gas, sodium, potassium, chloride, lactate dehydrogenase, aspartate aminotransferase, alanine aminotransferase, glucose and haemolysis index of samples conveyed simultaneously by PTS and by courier.

RESULTS

We recruited 30 patients from the sampling room and 40 patients from the intensive care unit. Transport through PTS resulted in a significant increase in aspartate aminotransferase and potassium without exceeding the limits of acceptability. Potassium was significantly more increased for samples transported in a higher speed line (p = .048) but without exceeding the limits of acceptability. No significant impact was noted on haemolysis indices. The pO2 variations due to PTS transportation exceeded the limit of acceptability with significant intra-individual variations.

CONCLUSION

Our PTS is validated for biochemistry tests results. It reduces turnaround times without affecting sample quality. However, the interpretation of arterial blood gas results should be careful for samples transported by PTS.

Effects of centrifugation prior to pneumatic tube system transport on routine biochemical and immunological tests of susceptibility to hemolysis

BACKGROUND

Pneumatic tube system (PTS) may be associated with preanalytical hemolysis. The objective of this study was to evaluate the effects of PTS on biochemical and immunological tests susceptible to hemolysis and try to find ways to reduce the result bias caused by PTS.

METHODS

Laboratory parameters were compared between PTS without centrifuging group, PTS after centrifuging group, PTS with serum group, and hand-delivered (HD) group. Studies were performed to access the influence of different PTS transport frequencies on laboratory assays.

RESULTS

PTS transportation resulted in obviously increase in LDH (lactate dehydrogenase) and NSE (neuron-specific enolase) results (LDH: Bias = 17.95%, 95% confidence interval (CI) = -3.13-39.02; p < 0.001; NSE: Bias = 64.26%, 95% CI = -21.29-149.82; p < 0.001; respectively). After pre-centrifugation, no statistical difference was observed in LDH results (Bias = 2.83%, 95% CI = -13.00-18.65; p = 0.737). However, the bias of NSE still reach 19.16% (95% CI = -41.78-80.11), which exceeded the clinical acceptable range (p = 0.017). Both LDH(p = 0.931) and NSE(p > 0.999) show no statistical difference between PTS with serum group and HD group (LDH: Bias = -1.60%, 95% CI = -6.00-2.81; NSE: Bias = -3.68%, 95% CI = -11.35-3.99).

CONCLUSION

PTS can lead to falsely increased LDH and NSE test results. Only loading the centrifuged upper serum in new tubes during PTS transport can eliminate the results bias of NSE.

Investigation of the effects of pneumatic tube transport system on routine biochemistry, hematology, and coagulation tests in Ankara City Hospital

OBJECTIVES

Academics are far from a consensus regarding the effects of pneumatic tube system (PTS) delivery on sample integrity and laboratory test results. As for the reasons for conflicting opinions, each PTS is uniquely designed, sample tubes and patient characteristics differ among studies. This study aims to validate the PTS utilized in Ankara City Hospital for routine chemistry, coagulation, and hematology tests by comparing samples delivered via PTS and porter.

METHODS

The study comprises 50 healthy volunteers. Blood samples were drawn into three biochemistry, two coagulation, and two hemogram tubes from each participant. Each of the duplicate samples was transferred to the emergency laboratory via Swiss log PTS (aka PTS-immediately) or by a porter. The last of the biochemistry tubes were delivered via the PTS, upon completion of coagulation of the blood (aka PTS-after). The results of the analysis in these groups were compared with multiple statistical analyses.

RESULTS

The study did not reveal any correlation between the PTS and serum hemolysis index. There were statistically significant differences in several biochemistry tests. However, none of them reached the clinical significance threshold. Basophil and large unidentified cell (LUC) tests had poor correlations (r=0.47 and r=0.60; respectively) and reached clinical significance threshold (the average percentages of bias, 10.2%, and 15.4%, respectively). The remainder of the hematology and coagulation parameters did not reach clinical significance level either.

CONCLUSIONS

The modern PTS validated in this study is safe for sample transportation for routine chemistry, coagulation, and hematology tests frequently requested in healthy individuals except for basophil and LUC.

Effects of a pneumatic tube system on the hemolysis of blood samples: a PRISMA-compliant meta-analysis

Many studies have explored how using a pneumatic tube system (PTS) is related to the hemolysis of blood samples, but their conclusions have been inconsistent. This meta-analysis was to clarify whether using a PTS induces the hemolysis of blood samples. The PubMed, Embase, Scopus, CNKI, CqVip, SinoMed and WanFang databases were searched for studies published between January 1970 and August 2019. The primary outcomes were the hemolysis rate and hemolysis index of blood samples after applying a PTS and manual transportation. We estimated the pooled risk ratio (RR) and the standardized mean difference (SMD), using random-effects models. This meta-analysis included 29 studies covering 3121 blood samples. No significant differences were found between the PTS and manual-transportation groups in the hemolysis rate [RR: 0.99, 95% confidence interval (CI): 0.57 to 1.70], hemolysis index (SMD: 0.19, 95% CI: -0.00 to 0.38), or level of potassium (SMD: 0.05, 95% CI: -0.03 to 0.12), alanine aminotransferase (SMD: 0.00, 95% CI: -0.10 to 0.11), or aspartate aminotransferase (SMD: 0.04, 95% CI: -0.08 to 0.17). However, lactate dehydrogenase (LDH) level was significantly higher in the PTS group than in the manual-transportation group (SMD: 0.20, 95% CI: 0.06 to 0.34). Subgroup analysis revealed that the LDH level was clearly higher in the PTS group than in the manual-transportation group only when the PTS speed was ≥6 m/s or when the PTS distance was ≥250 m. According to this meta-analysis, PTSs were associated with alterations in LDH measurements, so it is sensible that each hospital validates and monitors their PTSs.

Pneumatic tube transport of blood samples affects global hemostasis and platelet function assays

INTRODUCTION

Pneumatic tube systems (PTS) are frequently used for rapid and cost-effective transportation of blood samples to the clinical laboratory. The impact of PTS transport on platelet function measured by the Multiplate system and global hemostasis measured by the TEG 5000 was evaluated.

METHODS

Paired samples from healthy adult individuals were obtained at two study sites: Rigshospitalet (RH) and Nordsjaellands Hospital (NOH). One sample was transported by PTS and one manually (non-PTS). Platelet function was assessed by platelet aggregation (Multiplate) and global hemostasis was assessed by a variety of thrombelastography (TEG) assays. Multiplate (n = 39) and TEG (n = 32) analysis was performed at site RH, and Multiplate (n = 28) analysis was performed at site NOH.

RESULTS

A significant higher agonist-induced platelet aggregation was found for PTS samples compared to manual transport at site NOH (P < .02, all agonists). No significant difference was found at site RH (P > .05, all agonists). For Kaolin TEG, samples transported by PTS showed a significant lower R-time and higher Angle (P < .001). No significant differences in MA and LY30 was found (P > .05). ACT of RapidTEG was significantly reduced (P = .001) and MA of Functional Fibrinogen TEG was significantly increased (P < .001) after PTS transport. No significant impact of PTS was observed for TEG assays with heparinase (P > .05).

CONCLUSIONS

Depending on the type of PTS, transportation by PTS affected platelet aggregation measured by Multiplate. Furthermore, PTS alters TEG parameters possibly reflecting coagulation factors. Clinical laboratories should evaluate the effect of the local PTS on Multiplate and TEG results.

Falsely decreased FVIII activity following pneumatic tube transport

INTRODUCTION

The pneumatic tube system (PTS) is widely used for sample delivery. We aimed to investigate the impacts of PTS on hemostasis assays.

METHODS

Triplicate samples from 30 healthy volunteers were delivered to the core laboratory manually by human courier or via the 500 m long-distance PTS or via the 1000 m long-distance PTS. Comparisons of 19 hemostasis tests were conducted.

RESULTS

Although PT, INR, APTT, FII, FV, FVII FIX, FX, FXII, DD, α2-PI, and PC had statistical significance (all P < .05), all had low average bias remaining within clinical acceptable limits. PTS transportation only resulted in a statistically significant and clinically relevant decrease in FVIII activity. In the 500 m-PTS group, 66.7% (20/30) of samples for FVIII testing had a bias greater than 8.3%. Moreover, in the 1000 m-PTS group, 96.7% (29/30) of samples had a bias of over 8.3%, and the maximal bias achieved 42.1%.

CONCLUSIONS

Pneumatic tube system in our institution could be used to deliver blood samples for hemostasis tests evaluated in this study except FVIII activity assay.

A Comparative Study of Blood Sampling From Venipuncture and Short Peripheral Catheters in Pediatric Inpatients

This prospective, comparative study examined blood test results, hemolysis rates, and patient perceptions related to 2 blood sampling methods in pediatric inpatients (N = 95). Blood specimens were drawn via venipuncture and a short peripheral catheter used for fluid administration. Results revealed no significant differences in potassium and glucose levels. No clinically significant difference in hemoglobin was noted. Hemolysis rates were 4% for venipuncture samples and 15% when drawn from peripheral catheters. One catheter became occluded after a blood draw. Patients/parents rated distress and dissatisfaction with venipuncture as significantly greater compared with short peripheral catheter blood sampling (P < .001).

Use of clinical data and acceleration profiles to validate pneumatic transportation systems

Background

Modern pneumatic transportation systems (PTSs) are widely used in hospitals for rapid blood sample transportation. The use of PTS may affect sample integrity. Impact on sample integrity in relation to hemolysis and platelet assays was investigated and also, we wish to outline a process-based and outcome-based validation model for this preanalytical component.

Methods

The effect of PTS was evaluated by drawing duplicate blood samples from healthy volunteers, one sent by PTS and the other transported manually to the core laboratory. Markers of hemolysis (potassium, lactate dehydrogenase [LD] and hemolysis index [HI]) and platelet function and activation were assessed. Historic laboratory test results of hemolysis markers measured before and after implementation of PTS were compared. Furthermore, acceleration profiles during PTS and manual transportation were obtained from a mini g logger in a sample tube.

Results

Hand-carried samples experienced a maximum peak acceleration of 5 g, while peaks at almost 15 g were observed for PTS. No differences were detected in results of potassium, LD, platelet function and activation between PTS and manual transport. Using past laboratory data, differences in potassium and LD significantly differed before and after PTS installation for all three lines evaluated. However, these estimated differences were not clinically significant.

Conclusions

In this study, we found no evidence of PTS-induced hemolysis or impact on platelet function or activation assays. Further, we did not find any clinically significant changes indicating an acceleration-dependent impact on blood sample quality. Quality assurance of PTS can be performed by surveilling outcome markers such as HI, potassium and LD.

Benefit of point of care testing in patient with major hyperleukocytosis

We report a case of a child with major leukocytosis (800 × 10⁹/L) leading to a false increase in plasma potassium and an unexpected spurious decrease in sodium. To suppress interferences due to hyperleukocytosis, our laboratory protocol consists of collecting blood on Clotting Activator/Serum tubes (CAS) and/or carrying samples by human courier. CAS tube analysis showed a decreased level of hyperkalemia and sodium within the reference range (consistent with point of care measurements). Pseudo-hyperkalemia caused by extreme hyperleukocytosis has been well documented and is caused by lysis of leukocytes and cell contents release (including potassium) into the plasma, especially regarding blast cells, which are at even higher risk of lysis. Pseudo-hyponatremia mechanism has not yet been described. This interference could be multifactorial; blast lysis could cause intracellular ionic content release, therefore, modifying extracellular fluid ionic ratios. To correct this interference, the hypothesis is that collecting samples on CAS tubes or monitoring patient using point of care analysis are the most efficient solutions, as transport mode did not resolve interference issues. We speculate that cell lysis related to interference is multifactorial but mainly caused by centrifugation. To confirm this, we would have liked to compare ion levels before and after centrifugation.

Alterations in the parameters of classic, global, and innovative assays of hemostasis caused by sample transportation via pneumatic tube system

BACKGROUND

Pneumatic tube system (PTS) is an integral part of large medical facilities providing rapid interconnection between units within the hospital and often used to transport blood samples. The aim of our study was to compare a wide variety of hemostasis assays to identify assays sensitive to this transport method and diagnostic relevance of the alterations.

METHODS

Routine coagulation and platelet tests (APTT, PT, TT, fibrinogen, light transmission aggregometry (LTA) with ADP, collagen, ristomycin and epinephrine), whole blood flow cytometry platelet function test (levels of CD42b, CD61, CD62P, PAC1, annexin V binding and mepacrine release) and global coagulation tests (thromboelastography (TEG), thrombin generation (TGT), thrombodynamics (TD), thrombodynamics-4D (TD-4D)) were determined in PTS- and manually transported samples of 10 healthy volunteers.

RESULTS

There were no significant differences between the values of APTT, PT, TT or fibrinogen between the samples transported by PTS or manually. The results for LTA demonstrated increase in the collagen-induced aggregation (84 ± 7% versus 73 ± 5%), while the response to epinephrine was decreased (58 ± 20% versus 72 ± 7.4%). Flow cytometry-based platelet function test showed a pre-activation of platelets by PTS-transportation while all integral assays of coagulation tested in the present study (TEG, TGT, TD, TD-4D) demonstrated a hypercoagulation shift.

CONCLUSIONS

Transportation by PTS caused significant shifts in parameters of functional and integral assays that exceeded parameter variation values and sometimes even were comparable to normal ranges. The results obtained in this study indicate that using of PTS for such assays may cause sufficient alterations of results and can lead to patient's mistreatment.

Blood Sample Transportation by Pneumatic Transportation Systems: A Systematic Literature Review

BACKGROUND

Pneumatic transportation systems (PTSs) are increasingly used for transportation of blood samples to the core laboratory. Many studies have investigated the impact of these systems on different types of analyses, but to elucidate whether PTSs in general are safe for transportation of blood samples, existing literature on the subject was systematically assessed.

METHODS

A systematic literature review was conducted following the preferred reporting items for systematic reviews and metaanalyses (PRISMA) Statement guidelines to gather studies investigating the impact of PTS on analyses in blood samples. Studies were extracted from PubMed and Embase. The search period ended November 2016.

RESULTS

A total of 39 studies were retrieved. Of these, only 12 studies were conducted on inpatients, mainly intensive care unit patients. Blood gases, hematology, and clinical chemistry were well investigated, whereas coagulation, rotational thromboelastometry, and platelet function in acutely ill patients were addressed by only 1 study each. Only a few parameters were affected in a clinically significant way (clotting time parameter in extrinsic system thromboelastometry, pO2 in blood gas, multiplate analysis, and the hemolysis index).

CONCLUSIONS

Owing to their high degree of heterogeneity, the retrieved studies were unable to supply evidence for the safety of using PTSs for blood sample transportation. In consequence, laboratories need to measure and document the actual acceleration forces in their existing PTS, instituting quality target thresholds for these measurements such as acceleration vector sums. Computer modeling might be applied to the evaluation of future PTS installations. With the increasing use of PTS, a harmonized, international recommendation on this topic is warranted.

Effects of one directional pneumatic tube system on routine hematology and chemistry parameters; A validation study at a tertiary care hospital

Background

The validation of sample stability through pneumatic tube system (PTS) is essential. The objective of this study was to evaluate the effects of PTS transportation on laboratory results.

Methods

Paired EDTA and SST blood samples were collected from 56 randomly selected patients. Laboratory parameters were compared between PTS group and hand-delivered group.

Results

No statistical differences were observed for complete blood counts, white blood cell differential parameters, erythrocyte sedimentation rate and most chemistry parameters between PTS and hand-delivered transport procedures. Mean platelet volume results obtained from samples transported through PTS were lower than that obtained from samples transported through hand-delivered method (P = 0.001). The results of aspartate aminotransferase (P = 0.000), lactate dehydrogenase (P = 0.000), and hemolysis index (P = 0.000) from PTS group were higher than that from hand-delivered group.

Conclusions

All laboratories should validate the stability of the results from samples according to transportation method.

The impact of pneumatic tube system on routine laboratory parameters: a systematic review and meta-analysis

Background:

Pneumatic tube system (PTS) is a widely used method of transporting blood samples in hospitals. The aim of this study was to evaluate the effects of the PTS transport in certain routine laboratory parameters as it has been implicated with hemolysis.

Methods:

A systematic review and a meta-analysis were conducted. PubMed and Scopus databases were searched (up until November 2016) to identify prospective studies evaluating the impact of PTS transport in hematological, biochemical and coagulation measurements. The random-effects model was used in the meta-analysis utilizing the mean difference (MD). Heterogeneity was quantitatively assessed using the Cohran’s

Results:

From a total of 282 studies identified by the searching procedure, 24 were finally included in the meta-analysis. The meta-analysis yielded statistically significant results for potassium (K) [MD=0.04 mmol/L; 95% confidence interval (CI)=0.015–0.065; p=0.002], lactate dehydrogenase (LDH) (MD=10.343 U/L; 95% CI=6.132–14.554; p<10

Conclusions:

This meta-analysis suggests that PTS may be associated with alterations in K, LDH and AST measurements. Although these findings may not have any significant clinical effect on laboratory results, it is wise that each hospital validates their PTS.

Extending laboratory automation to the wards: effect of an innovative pneumatic tube system on diagnostic samples and transport time

Background:

The innovative pneumatic tube system (iPTS) transports one sample at a time without the use of cartridges and allows rapid sending of samples directly into the bulk loader of a laboratory automation system (LAS). We investigated effects of the iPTS on samples and turn-around time (TAT).

Methods:

During transport, a mini data logger recorded the accelerations in three dimensions and reported them in arbitrary area under the curve (AUC) units. In addition representative quantities of clinical chemistry, hematology and coagulation were measured and compared in 20 blood sample pairs transported by iPTS and courier.

Results:

Samples transported by iPTS were brought to the laboratory (300 m) within 30 s without adverse effects on the samples. The information retrieved from the data logger showed a median AUC of 7 and 310 arbitrary units for courier and iPTS transport, respectively. This is considerably below the reported limit for noticeable hemolysis of 500 arbitrary units.

Conclusions:

iPTS reduces TAT by reducing the hands-on time and a fast transport. No differences in the measurement results were found for any of the investigated 36 analytes between courier and iPTS transport. Based on these findings the iPTS was cleared for clinical use in our hospital.

Influence of pneumatic tube system transport on routinely assessed and spectrophotometric cerebrospinal fluid parameters

BACKGROUND

Pneumatic tube systems (PTS) are widely used in many hospitals. Using PTS reduces turnaround time (TAT) and can improve patients' outcome.

METHODS

We investigated whether clinically significant differences could be observed in CSF samples transported by pneumatic tube in comparison with samples transported by hand. Two aliquots from one sample were sent by PTS and by hand from the department of neurology or neurosurgery and compared.

RESULTS

Routine cytological and biochemical assessment was compared in 27 cases. There were no statistically significant changes (transport by hand vs. PTS) in glucose levels [data are expressed as median (minimum-maximum)] at 3.7 (2.5-8.6) mmol/L vs. 3.6 (2.7-8.6) mmol/L, p=0.96 or lactate levels at 1.8 mmol/L (1.1-5.5) vs. 1.8 mmol/L (1.1-5.4). We observed a statistically significant decline in total protein levels in samples transported by PTS at 0.56 g/L (0.19-4.29) vs. 0.49 g/L (0.18-4.3), p=0.008. We observed no changes in erythrocyte count at 5/μL (0-40,000) vs. 5/μL (0-40,106), mononuclear cells at 2/μL (1-145) vs. 3/μL (1-152), or polynuclear cells at 0/μL (0-235) vs. 0/μL (0-352). Spectrophotometric examination was performed in 20 cases. There were no statistically significant differences (transport by hand vs. transport by PTS) in NOA at 0.002 (0.001-1.537) vs. 0.001 (0.001-1.528), p=0.95 or NBA at 0.001 (0.001-0.231) vs. 0.001 (0.001-0.276), p=0.675. Samples transported by PTS were delivered faster than samples transported by courier (transport by hand vs. PTS) at 25 min (10-153) vs. 15 min (4-110), p=0.002.

CONCLUSIONS

We found no significant changes in glucose, lactate levels and in any of the cytological parameters assessed, nor were statistically significant changes observed in the spectrophotometric parameters. We found a statistically significant decrease in total protein levels in samples transported by PTS. Transport by PTS can be faster than transport by hand.

Does Pneumatic Tube System Transport Contribute to Hemolysis in ED Blood Samples?

INTRODUCTION

Our goal was to determine if the hemolysis among blood samples obtained in an emergency department and then sent to the laboratory in a pneumatic tube system was different from those in samples that were hand-carried.

METHODS

The hemolysis index is measured on all samples submitted for potassium analysis. We queried our hospital laboratory database system (SunQuest(®)) for potassium results for specimens obtained between January 2014 and July 2014. From facility maintenance records, we identified periods of system downtime, during which specimens were hand-carried to the laboratory.

RESULTS

During the study period, 15,851 blood specimens were transported via our pneumatic tube system and 92 samples were hand delivered. The proportions of hemolyzed specimens in the two groups were not significantly different (13.6% vs. 13.1% [p=0.90]). Results were consistent when the criterion was limited to gross (3.3% vs 3.3% [p=0.99]) or mild (10.3% vs 9.8% [p=0.88]) hemolysis. The hemolysis rate showed minimal variation during the study period (12.6%-14.6%).

CONCLUSION

We found no statistical difference in the percentages of hemolyzed specimens transported by a pneumatic tube system or hand delivered to the laboratory. Certain features of pneumatic tube systems might contribute to hemolysis (e.g., speed, distance, packing material). Since each system is unique in design, we encourage medical facilities to consider whether their method of transport might contribute to hemolysis in samples obtained in the emergency department.

Heparinate but not serum tubes are susceptible to hemolysis by pneumatic tube transportation

Background:

Pneumatic tube transportation (PTT) may induce hemolysis (H) in blood samples. We aimed to compare the H degree before and after PTT implementation in our hospital.

Methods:

Hemolysis indices (HI) for all lithium-heparin plasma samples (P) drawn by the Emergency Department in 2-month periods were retrospectively collected and pre- (n=3579) and post-PTT (n=3469) results compared. The impact of PTT introduction was investigated on LDH [HI threshold (HIt), 25], conjugated bilirubin (cBIL) (HIt, 30), K (HIt, 100) and ALT (HIt, 125). In addition, HI retrieved for P and paired serum samples collected in silica clot activator tubes (S) from the same venipuncture were compared in pre- (n=501) and post-PTT (n=509) periods.

Results:

Median (5–95th percentile) HI in P was significantly higher in post-PTT period [7 (0–112) vs. 6 (0–82), p<0.001]. Results reported as ‘Hemolysis’ in P increased from 6.6% in pre-PTT to 9.4% in post-PTT (p<0.001). Investigated tests gave the following rejection rates (pre-PTT vs. post-PTT): LDH, 13.4% vs. 18.8%, p<0.001; cBIL, 9.4% vs. 27.0%, p<0.05; K, 3.7% vs. 5.6%, p<0.001; ALT, 2.9% vs. 4.4%, p<0.01. The slightly higher susceptibility to H of S compared to paired P found in the pre-PTT [9 (1–64) vs. 6 (0–85)] was not confirmed in the post-PTT period [7 (0–90) vs. 8 (1–72)], in which median HI in S was significantly lower (p<0.001) than in pre-PTT.

Conclusions:

In our setting PTT promotes H in P, increasing the rate of rejected tests. The use of S appears to protect against the hemolysing effect of PTT.

Hemolysis associated with pneumatic tube system transport for blood samples

Objective: The frequency of hemolysis of blood samples may be increased by transport in a pneumatic tube system. The purpose of this study was to evaluate the effect of pneumatic tube system transport on hemolysis of blood samples.

Methods: Blood samples were transported from the emergency department to the hospital laboratory manually by hospital staff (49 patients) or with a pneumatic tube system (53 patients). The hemolysis index and serum chemistry studies were performed on the blood samples and compared between the different methods of transport.

Results: The blood samples that were transported by the pneumatic tube system had a greater frequency of hemolysis and greater mean serum potassium and median creatinine, aspartate aminotransferase, and lactate dehydrogenase levels than samples transported manually.

Conclusion: Blood samples transported from the emergency department to the hospital laboratory by a pneumatic tube system may have a greater frequency of hemolysis than samples transported manually. This may necessitate repeat phlebotomy and cause a delay in completing the laboratory analysis.

Pneumatic tube transport affects platelet function measured by multiplate electrode aggregometry

Multiple electrode aggregometry (MEA) is used to measure platelet function. Pneumatic tube transport systems (PTS) for delivery of patient samples to a central laboratory are often used to reduce turnaround time for vital analyses. We evaluated the effects of PTS transport on platelet function as measured by MEA. Duplicate samples were collected from 58 individuals. One sample was sent using PTS and the other was carried by personnel to the lab. Platelet function was measured by means of a Multiplate® analyzer using the ADP test, ASPI test, COL test, RISTO test and TRAP test. Samples transported using PTS showed a reduction of AUC-values of up to a 100% of the average as compared to samples carried by personnel and a majority showed reductions of AUC-values greater than 20% of the average. Bias±95% limits of agreement for the ADP test were 26±56% of the average. Bias±95% limits of agreement for the ASPI test were 16±58% of the average. Bias±95% limits of agreement for the COL test were 20±54% of the average. Bias±95% limits of agreement for the RISTO were 14±79% of the average. Bias±95% limits of agreement for the TRAP test were 19±45% of the average. We conclude that PTS transport affect platelet activity as measured by MEA. We advise against clinical decisions regarding platelet function on the basis of samples sent by PTS in our hospital settings.